S2751-28TP-PWR-EI-AC (24个10/100Base-TX以太网端口,4个千兆SFP,2个复用的10/100/1000Base-T以太网端口Combo,12端口PoE+,交流供电) S2751-28TP-PWR-EI-AC 全网管 1U (24个10 100Base-TX以太网端口,4个千兆SFP,2个复用的10 100 1000Base-T以太网端口Combo,12端口PoE+,交流供电)